The present invention relates in general to a power supply cord retracting and dispensing apparatus and a method of managing the tension of the power supply cord in an appliance. Specifically, the apparatus and method for managing the tension of the power cord involves retracting and dispensing the power supply cord in association with movements of the appliance relative to an electrical outlet.
In the typical autonomous or self-propelled appliance or robot, in order to dispense the electric cord from the appliance, the cord is forcibly pulled from a cord reel as the appliance moves away from an electrical outlet. In order to retract the cord into the appliance, a mechanism is pressed or actuated to cause the cord to be drawn into the appliance at a fairly high speed as urged by a spiral plate spring. As the distance increases between the appliance and the outlet, more tension is given to the cord by the spiral plate spring, thereby resulting in a higher speed by which the cord is drawn back into the appliance. Thus, in a conventional self-propelled corded appliance there are shortcomings in the way a power cord is dispensed from, and retracted towards, the appliance.
Accordingly, it is considered desirable to develop a new and improved cord management apparatus and method to solve the above problems. Additionally, it is an object of the present invention to maintain and manage a minimal force of tension on the cord at all times regardless of a distance between the appliance and the outlet.
One aspect of the present invention relates to an auto-feed/rewind electric cord reel. More particularly in accordance with this aspect of the invention, an apparatus is provided for controlling a power supply cord of an appliance comprising a reel bracket on which a cord reel is rotatably mounted. A motor bracket is movably mounted in relation to the reel bracket. A linkage connects the reel bracket to the motor bracket. A first motor selectively actuates the linkage and moves the motor bracket in relation to the reel bracket. A second motor is provided, spaced from the first motor, for driving an assembly which selectively rotates the cord reel in at least one direction.
In accordance with another aspect of the invention, a method is provided for managing the tension on an electric power supply cord of an appliance, the cord being wound on a rotary cord reel carried by the appliance for effecting a dispensing and a retraction of the cord. The method comprises the steps of: sensing an axial force on the cord corresponding to movements of the appliance; selectively retracting the cord when no axial force on the cord is sensed; and, selectively dispensing the cord when an axial tension of a predetermined minimum amount is sensed.